Distributed antenna systems over general use network infrastructures

ABSTRACT

Distributed antenna systems over general use network infrastructures are provided. In one embodiment, a distributed antenna system comprises: a central area node (CAN) coupled to a backbone network, wherein the CAN is configured to communicatively couple to at least one base station via the network, and to communicatively couple to at least one wireless access point via the network. The distributed antenna system is configured to use virtual cables implemented using the network, each of the virtual cables defined by a respective dedicated data channel on the network. The CAN is coupled to the base station and wireless access point using at least some of the virtual cables. Downlink and uplink transport signals are transported between the CAN and the wireless access point through said virtual cables. The downlink transport signals are generated from base station downlink signals and base station uplink signals are generated from the uplink transport signals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. Patent Application claims priority to, and the benefit of,U.S. Provisional Patent Application No. 62/808,125, titled “DISTRIBUTEDANTENNA SYSTEMS OVER GENERAL USE NETWORK INFRASTRUCTURES”, filed on Feb.20, 2019, which is incorporated herein by reference in its entirety.

BACKGROUND

A Distributed Antenna System (DAS) typically includes at least onemaster unit that is communicatively coupled with a plurality of remoteantenna units. A DAS is typically used to improve the wireless servicecoverage provided by one or more base stations that are coupled to theDAS through the master unit. The wireless service provided by the basestations can be included, for example, telecommunications and dataservices such as commercial cellular service and/or public safetywireless communications. The cable infrastructure between the masterunit and the remote units typically comprises a point-to-multi-pointsystem of dedicated cables (for example, copper or fiber optic) thatconnects the master unit with the plurality of remote units. Theutilization of a dedicated cable system designed specifically for use inthe DAS ensures that that the DAS infrastructure will be able to supportthe transport of communications traffic between the base stations andthe remote antenna units. However, such a dedicated cable system hasseveral inherent drawbacks. First, the dedicated cable system representsan investment in equipment resources that serves only a single purposeand cannot be leveraged to support other non-DAS communications needs.Second, the dedicated cable system must be designed with handling amaximum communications traffic load in mind, even though the normalexpected communications traffic load may be considerably less. Third, ifan extension of the DAS is needed, the dedicated cable system will needto be upgraded by installing additional lengths of dedicated cable.

SUMMARY

In one embodiment, a distributed antenna system comprises: a centralarea node communicatively coupled to a backbone network, wherein thecentral area node is configured to communicatively couple to at leastone base station via the backbone network, the central area node furtherconfigured to communicatively couple to at least one wireless accesspoint via the backbone network; wherein the distributed antenna systemis configured to use a plurality of virtual cables implemented using thebackbone network, each of the plurality of virtual cables defined by arespective dedicated data channel on the backbone network; wherein thecentral area node is communicatively coupled to the at least one basestation and the at least one wireless access point using at least someof the virtual cables; and wherein downlink transport signals and uplinktransport signals are transported between the central area node and thewireless access point through said at least some of the virtual cables,wherein the downlink transport signals are generated from base stationdownlink signals and base station uplink signals are generated from theuplink transport signals.

DRAWINGS

Embodiments of the present disclosure can be more easily understood andfurther advantages and uses thereof more readily apparent, whenconsidered in view of the description of the preferred embodiments andthe following figures in which:

FIG. 1 is a diagram illustrating an example Distributed Antenna Systemembodiment.

FIGS. 1A, 1B and 1C are diagrams illustrating alternate implementationsof an example Distributed Antenna System embodiment.

FIG. 2 is a diagram for an example configuration illustrating increasingservice capacity of an example Distributed Antenna System embodiment.

FIG. 3 is a diagram for an example configuration illustrating increasingcoverage area of an example Distributed Antenna System embodiment.

FIG. 4 is a diagram illustrating an example DAS configuration comprisingmultiple DAS supported over a common backbone network.

FIG. 5 is a diagram illustrating and example common DAS managementsystem.

FIG. 6 is flow chart illustrating an example method embodiment for adistributed antenna system.

FIG. 7 is a diagram illustrating an example distributed BTS embodiment.

FIGS. 8, 9 and 10 are diagrams illustrating embodiments with examplealternate architectures comprising interfaces between a distributed BTSand a DAS.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown byway of specific illustrative embodiments in which the embodiments may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the embodiments, and it isto be understood that other embodiments may be utilized and thatlogical, mechanical and electrical changes may be made without departingfrom the scope of the present disclosure. The following detaileddescription is, therefore, not to be taken in a limiting sense.

As described below, at least some of the embodiments of the presentdisclosure provide for distributed antenna systems that, at least inpart, replaces the use of dedicated cables to transport data betweencomponents of a DAS by instead using general purpose publicinfrastructure backbone networks to establish virtual cable connectionsbetween DAS components. Such public infrastructure backbone networks aretypically used to carry digital data for services to the public such asbut not limited to telephony, internet, television and other data and/orentertainment services. With one or more of the embodiments disclosedherein, such backbone networks are leveraged to further transport thedigital transmission of RF signals of a DAS. Such embodiments provide anadvantage in flexibility over DAS that employ dedicated cable system.For example, transport resources between DAS components can be allocatedon the backbone network according to actual need. DAS re-configurationscan be performed virtually without the need to install new cables. DAScoverage expansions and extensions can be achieved by establishingconnections between new DAS components and the backbone network. DAScomponents can be distributed across the backbone network and need nothave a physical proximity with each other. Multiple DAS systems can beimplemented via a backbone network, and DAS components can bere-assigned between different DAS systems without cable changes, orredundancy scenarios established. Moreover, as explained below, a commonmanagement system (such as an ONAP, Open Networking Automation Platform,for example) can coordinate both changes in the infrastructure and theDAS system (independent of equipment component suppliers).

FIG. 1 is a diagram illustrating a Distributed Antenna System 100 of oneembodiment of the present disclosure. As shown in FIG. 1, in oneimplementation DAS 100 comprises a wide-area integration node (WIN) 110,a central area node (CAN) 120, a transport extension node (TEN) 130, anda plurality of wireless access points 140. The WIN 110 and CAN 120operate in conjunction with each other to implement the master unit (MU)function for DAS 100 that establishes communications with one or morebase stations 105. In the particular embodiment shown in FIG. 1, the oneor more base stations 105 coupled to WIN 110 include the three basestations BTS S1, BTS S2 and BTS S3. The plurality of access points 140define the remote antenna units of the DAS 100 which establish wirelessconnectivity with the one or more user devices (UD) 101 (such as tabletsor cellular telephone, for example) located within the coverage area 102of the DAS 100.

In the downlink direction, DAS 100 is configured to receive downlinkradio frequency signals from the base stations 105. These signals mayalso be referred to as “base station downlink signals.” Each basestation downlink signal includes one or more radio frequency channelsused for communicating in the downlink direction with user devices 101over a relevant wireless air interface. In the uplink direction, DAS 100is configured to receive respective uplink radio frequency signals fromthe user equipment 101 within the coverage area of the DAS 100, andtransport those signals as “base station uplink signals” to the basestations 105.

In the example embodiment of FIG. 1, the WIN 110, CAN 120 and TEN 130are each communicatively coupled to a backbone network 108. In someembodiments, the backbone network 108 may comprise a Synchronous DigitalHierarchy (SDH), Sonet (Synchronous Optical Network), Optical TransportNetwork (OTN) or other network technology. In some embodiments, thebackbone network 108 may comprise the Internet or other publicinfrastructure network, for example, operated by a government or privateutility entity, that transports data for a plurality of differentservices and for a plurality of different entities. In some embodiments,the backbone network 108 is an optical network and each of the WIN 110,CAN 120 and TEN 130 may be coupled to the backbone network 108 via arespective add/drop multiplexer (ADM) 106. In some embodiments, thebackbone network 108 may include one or more segments that comprise anEthernet network, or may be entirely implemented as an Ethernet network.Therefore, for any of the embodiments described herein, the respectiveadd/drop multiplexer (ADM) 106 may be replaced by an Ethernet switch 106for those instances where the BTS 105, WIN 110, CAN 120, TEN 130 and/orAP 140 are coupled to portions of the backbone network 108 comprisingthe Ethernet network. In some embodiments, the Ethernet switch maysupport for one or more quality of service standards or techniques.

With embodiments of the present disclosure, bandwidth on the backbonenetwork 108 is allocated to the operation of the DAS 100 in the form ofvirtual cables 112 created between the WIN 110, CAN 120 and TEN 130.These virtual cables 112 are not dedicated physical cables. Instead, thevirtual cables 112 each define dedicated data channels on the backbonenetwork 108 for carrying digital transmission of RF signals and controldata between components of the DAS 100. Accordingly, in someembodiments, each virtual cable 112 may comprise distinct uplink anddownlink communications subchannels. In the embodiment of FIG. 1, afirst virtual cable 112 couples the WIN 110 to the CAN 120 while asecond virtual cable 112 couples the CAN 120 to the TEN 130.

Typically, each base station downlink signal is received at the WIN 110from the one or more base stations 105 as analog radio frequency (RF)signals, though in some embodiments one or more of the base stationsignals are received in a digital form (for example, in a digitalbaseband form complying with the Common Public Radio Interface (“CPRI”)protocol, Open Radio Equipment Interface (“ORI”) protocol, the Open BaseStation Standard Initiative (“OBSAI”) protocol, or other protocol). Thebase station downlink signals are digitized or otherwise formatted bythe WIN 110 into a digital signal, and the resulting downlink transportsignal transported to the CAN 120 over the first virtual cable 112 thatcouples the WIN 110 to the CAN 120. The CAN 120 functions as thehead-end unit of the DAS 100 and may be used to coordinate theoperations of WIN 110, TEN 130 and wireless access points 140. Forexample, the CAN 120 may operate to forward downlink transport signalsto TEN 130 over the second virtual cable 112 that couples the CAN 120 toTEN 130 and receive uplink transport signals from the TEN 130 over thesecond virtual cable 112. In some embodiments the CAN 120 implements aswitching matrix that provides for switching services carried throughand/or between the virtual cables 112. In some embodiments the CAN 120implements functionalities that permit copying received downlink signalsto multiple wireless access points 140 destinations, and to combineuplink signals received from multiple wireless access points 140. TheCAN 120 may also further include interfaces or other means for providingexternal access to the DAS 100 (for example, via ONAP as describedbelow).

In the embodiment shown in FIG. 1, the DAS 100 includes the single TEN130. However, in alternate embodiments discussed below, the DAS 100 mayinclude multiple TEN units in which case virtual cables 112 for each TENwould be established to the CAN 120 through the backbone network 108.

From the TEN 130, patch cables 132 are distributed to one or moreantenna locations where access points 140 are deployed. Each accesspoint 140 receives the base station downlink RF signals, converts thedigital signals to analog radio frequency (RF) signals for over-the-airtransmission, and broadcasts (radiates) the base station downlinksignals as wireless downlink RF signals to user equipment 101 within thecoverage area 102 of the DAS 100.

Uplink RF signals transmitted by the user equipment 101 located withinthe coverage area 102 of the DAS 100 are received by the access points140, digitized or otherwise converted to digital signals, and receivedby the TEN 130. These uplink transport signals are formatted by the TEN130 for transport to the CAN 120 over the virtual cable 112 that couplesthe TEN 130 to the CAN 120. The CAN 120 processes the digital uplinksignals received from the TEN for further transport to the WIN 110. Thisprocessing may involve, among other things, combining or summing uplinksignals received from the multiple access points 140 in order to producea composite uplink base station signal. The composite base stationuplink signal is transported to the WIN 110 over the virtual cable 112that couples the WIN 110 to the CAN 120. Ultimately, composite basestation uplink signals are output from the WIN 110 to the one or morebase stations 105. In this way, the DAS 100 increases the coverage areaavailable for both uplink and downlink communications between userequipment 101 and the base stations 105.

Is should be understood that in alternate embodiments, one or both ofWIN and TEN may be omitted as optional. For example, FIG. 1A shown analternate implementation of DAS 100 where the virtual cables 112 areused to couple the CAN 120 directly to the access points 140 without anintervening TEN 130. In such implementations, the access points 140 mayeach be connected to the backbone network 108 directly, such as throughrespective add-drop multiplexers 106. Such an alternate configurationmay be utilized for an alternate implementation for any of the otherembodiments disclosed herein, or for use in combination with any of theother embodiments disclosed herein.

In some alternate implementations, shown in FIG. 1B, virtual cables 112may also potentially be used to couple the CAN 120 directly to one ormore base stations 105 without an intervening WIN 110. That is, wherethe base stations 105 are configured to communicate their uplink anddownlink base stations signals as digital signals, those signals may betransported by virtual cables 112 directly from such a base station tothe CAN 120. In such implementations, the base stations 105 may each beconnected to the backbone network 108 directly, such as throughrespective add-drop multiplexers 106.

In still other alternate implementations, such as shown in FIG. 1C,virtual cables 112 may also potentially be used to couple the TEN 130 toone or more of the access points 140 over backbone network 108 insteadof using patch cables 132. In some embodiments, those access points 140communicating with TEN 130 via virtual cables 112 may be connected tothe backbone network 108 directly, such as through respective add-dropmultiplexers 106.

Also as shown in FIG. 1C, in some embodiments virtual cables 112 mayalso potentially be used to couple a WIN 110 to one or more of the basestations 105 over backbone network 108. Those base stations 105communicating with WIN 110 via virtual cables 112 may be connected tothe backbone network 108 directly, such as through respective add-dropmultiplexers 106. Those base stations 105 utilizing virtual cables 112to communicate with WIN 110 are configured to communicate their uplinkand downlink base stations signals as digital signals (for example,using a CPRI protocol).

As mentioned above, the architecture presented by the DAS 100, in any ofthe FIGS. 1 and 1A-1C, have the benefit of providing flexibility in itsability to adapt the DAS to changing operator needs while avoiding theinstallation and/or reconfiguration of dedicated cables between DAScomponents. It should be understood that the alternate configurationsdescribed with respect to FIGS. 1 and 1A-1C may be used, either whollyor in part, in conjunction and/or in combination with each other.

FIG. 2 is a diagram illustrating an example configuration of the DAS 100that increases the service capacity available to user devices 101 withinthe coverage area 102 supported by the access points 140. In particular,the DAS 100 has been modified in FIG. 2 to include the addition of asecond WIN (shown at WIN 210) onto the backbone network 108. While WIN110 has access to the services of the base stations BTS S1, BTS S2 andBTS S3, the WIN 210 has access to the services of base stations BTS S4,BTS S5 and BTS S6 shown at 205. By reconfiguring the backbone network108 to establish a new virtual cable 212 between WIN 210 and CAN 120,the CAN 120 may now distribute the combined services of base stations105 and 205 to the user devices 101 within the coverage area 102supported by the access points 140. It should be appreciated that in anyof the embodiments described herein, the CAN 120 may be configured tomanage which base station 105 services are accessible through which ofthe access points 140. For example, in one implementation, the CAN 120may pair the services of BTS S1 to a first access point 140 (AP 1), BTSS2 to a second access point 140 (AP 2), and BTS S3 to a third accesspoint 140 (AP 3). At the same time, the additional services of basestations BTS S4, BTS S5 and BTS S6 may similarly be distributed by TEN130 to specific access points. For example, the services of BTS S4 maybe paired to the first access point 140 (AP 1), BTS S5 to the secondaccess point 140 (AP 2), and BTS S6 to the third access point 104(AP 3).In other implementations, services from a base station may bedistributed to, and accessible from, multiple, or all, access points140.

To accommodate the extra network traffic due to this increase in servicecapacity, the bandwidth capacity of the virtual cable 112 between theCAN 120 and the TEN 130 may be adjusted to allocate addition backbonenetwork bandwidth capacity. This service expansion benefiting the userdevices 101 within the coverage area 102 of DAS 100 is thus accomplishedwithout the necessity of installing or reconfiguring physical cablingbetween DAS 100 components. Moreover, the WIN 210 may be installed at alocation where connection to the new base stations (BTS S4, BTS S5 andBTS S6) and the backbone network 108 is most convenient.

FIG. 3 is a diagram illustrating another example configuration of theDAS 100 that increases the effective area of the coverage area 102 byincreasing the number of access points, as shown at 340. In thisembodiment, an additional TEN (shown at TEN 330) is coupled onto thebackbone network 108. From the TEN 330, patch cables 332 are distributedto the additional antenna locations where access points 340 aredeployed. By reconfiguring the backbone network 108 to establish anothervirtual cable 312 between CAN 120 and TEN 330, the CAN 120 may nowfurther distribute the services of base stations 105 and 205 to the userdevices 101 within the expanded coverage area 103 supported by thecombination of access points 140 and access points 340. This coveragearea 102 expansion of DAS 100 is thus accomplished without the necessityof installing or reconfiguring physical cabling between DAS 100components.

FIG. 4 is a diagram illustrating an example DAS configuration wheremultiple DAS are supported over the backbone network 108. In thisexample embodiment, the first DAS 100 comprises at least the WIN 110,CAN 120, TEN 130, and the plurality of access points 140. In someimplementations, the DAS 100 may optionally be configured withadditional WIN and/or TEN coupled to the backbone network 108 such asillustrated in FIGS. 2 and 3 above. A second DAS 400 comprises at leasta WIN 410, CAN 420, TEN 430, and a plurality of access points 440, eachof which function in an equivalent manner to WIN 110, CAN 120, TEN 130and access point 140. One or more base stations 405 are coupled to theWIN 410. In the particular embodiment shown in FIG. 4, the one or morebase stations 405 include the three base stations BTS S4, BTS S5 and BTSS6. From the TEN 430, patch cables 432 are distributed to the additionalantenna locations where the access points 440 are deployed. DAS 400, viathe access points 440, provide wirelesses services to user devices 101within coverage area 402.

In the downlink direction, DAS 400 is configured to receive downlinkradio frequency signals from the base stations 405. These signals mayalso be referred to as “base station downlink signals.” Each basestation downlink signal includes one or more radio frequency channelsused for communicating in the downlink direction with user devices 101over a relevant wireless air interface. In the uplink direction, DAS 400is configured to receive respective uplink radio frequency signals fromthe user equipment 101 within the coverage area 402 of the DAS 400, andtransport those signals as “base station uplink signals” to the basestations 405.

As with DAS 100, bandwidth on the backbone network 108 is allocated tothe operation of the DAS 400 in the form of virtual cables 412 createdbetween the WIN 410, CAN 420 and TEN 430. These virtual cables 412 eachdefine dedicated data channels on the backbone network 108 for carryingdigital transmission of RF signals and control data between componentsof the DAS 400. Accordingly, in some embodiments, each virtual cable 412may comprise distinct uplink and downlink communications subchannels. Inthe embodiment of FIG. 4, a first virtual cable 412 couples the WIN 410to the CAN 420 while a second virtual cable 412 couples the CAN 420 tothe TEN 430. In some implementations, the DAS 400 may optionally beconfigured with additional WIN and/or TEN coupled to the backbonenetwork 108 in the same manner as illustrated in FIGS. 2 and 3 above.

In this configuration, multiple DAS systems 100 and 400 aresimultaneously supported over the common backbone network 108. Moreover,this configuration supports the ability to selectively reassign DAScomponents from one DAS to the other by realigning network to rearrangethe connection of virtual cables. For example, in one implementation theaccess points 140 may be located at an office building and normally areprovided service from base stations 105. The access points 440 may belocated at an events stadium and normally provided service from basestations 405. During an event at the event stadium, base stations 105can be realigned to increase the coverage capacity at the stadium, forexample, by disconnecting the virtual cable 112 from WIN 110 to CAN 120,and creating a new virtual cable (shown at 415) from WIN 110 to CAN 420so that the services of base stations 105 become available via accesspoints 440 (in addition to the services of base stations 405).Alternatively, in some embodiments, the configuration facilitatesredundancy scenarios in the operators of DAS 100 and 400 may shift anyof the DAS components from one DAS to the other should a failure of aCAN, TEN, or WIN, or other data link failure occur.

As shown in FIG. 5, in some embodiments a common management system 500(such as an ONAP, Open Networking Automation Platform, for example) canbe included to coordinate changes and reconfigurations of a DASinfrastructure and WIN, CAN and TEN components such as any of thosedisclosed with respect to FIGS. 1-4. Moreover, in some embodiments, thecommon management system 500 can coordinate changes and reconfigurationsof any of the access point 140. For example, as shown in FIG. 5, the CAN520 may be in communication with an Access Point 550 (either directly orvia TEN 530) so that the common management system 500 can send commandsto the CAN 520 which are used to implement reconfiguration of the AP550. The common management system 500 also manages the underlyingbackbone network 108 at least with respect to creating and modifyingvirtual cables 112.

For example, in one embodiment a network operator by accessing thecommon management system 500 can send control commands to a CAN tomanage and obtain status information about the DAS (for example, aboutof the various WIN, CAN, TEN components shown in FIG. 5 as WIN 510, CAN520, TEN 530). The common management system 500 may be programmed toprovide a unified interface to the components of the DAS by interfacingwith a management interface 505 in the CAN 520. The CAN 520 in responseto commands from the common management system 500 initiates any changesto the DAS and/or collects information by coordinating with the WIN 510and TEN 530. Similarly, the common management system 500 may communicatewith a backbone network management interface 540 to reconfigure aspectsof the backbone network 108, such as for virtual cable 112 adding,deleting, switching or reconfiguration (for example, to increase ordecrease their bandwidth or other parameter). In some embodiments,management command and information traffic between the common managementsystem 500 and CAN 520 and/or the backbone network management interface540, may be carried over the backbone network 108 or may instead becarried over a separate network.

It should be understood that the alternate configurations described withrespect to FIGS. 1, 1A-1C and 2-5 may be used, either wholly or in part,in conjunction and/or in combination with each other. Moreover, isshould be understood that in some embodiments, the DAS may utilize acombination of virtual and physical cables.

FIG. 6 is an example embodiment for a method 600 for a distributedantenna system of the present disclosure. It should be understood thatthe features and elements described herein with respect to the methodshown in FIG. 6 and the accompanying description may be used inconjunction with, in combination with, or substituted for elements ofany of the other embodiments discussed herein, and vice versa. Further,it should be understood that the functions, structures and otherdescription of elements associated with embodiments of FIG. 6 may applyto like named or described elements for any of the FIGS. 1, 1A-1C, 2-5and embodiments described therein, and vice versa.

The method begins at 610 with communicatively coupling a central areanode of the distributed antenna system to a backbone network, whereinthe central area node is configured to communicatively couple to atleast one base station via the backbone network, the central area nodefurther configured to communicatively couple to at least one wirelessaccess point via the backbone network. Each base station downlink signalincludes one or more radio frequency channels used for communicating inthe downlink direction with user devices over a relevant wireless airinterface. In the uplink direction, the distributed antenna system isconfigured to receive respective uplink radio frequency signals from theuser equipment within the coverage area of the distributed antennasystem, and transport those signals as the base station uplink signalsto the base stations. In some embodiment, the method may also optionallyinclude communicatively coupling at least one wide-area integration nodeof the distributed antenna system to the backbone network. In that case,wide-area integration node can be configured to communicate base stationdownlink signals and base station uplink signals with the base station.The method may also optionally include communicatively coupling at leastone transport extension node of the distributed antenna system to thebackbone network, wherein the transport extension node is coupled to thewireless access points.

The method proceeds to 620 with establishing a plurality of virtualcables implemented using the backbone network, each of the plurality ofvirtual cables using a respective data channel of the backbone network,wherein the central area node is communicatively coupled to the at leastone base station and the at least wireless access point using at leastsome of the virtual cables. The backbone network may comprise aSynchronous Digital Hierarchy (SDH), Sonet (Synchronous OpticalNetwork), Optical Transport Network (OTN), Ethernet, or another networktechnology. In some embodiments, the backbone network may comprise theInternet or other public infrastructure network that transports data fora plurality of different services and for a plurality of differententities in addition to carrying traffic for the distributed antennasystem. In some embodiments, the backbone network may be operated by agovernment or private utility entity. In some embodiments, each of thewide-area integration node, a central area node and a central area nodemay be coupled to the backbone network via a respective add/dropmultiplexer.

The method proceeds to 630 with transporting downlink transport signalsand uplink transport signals between the central area node and the atleast one wireless access point through said at least some of theplurality of virtual cables, wherein the downlink transport signals aregenerated from base station downlink signals from the to at least onebase station and base station uplink signals to the at least one basestation are generated from the uplink transport signals. As mentionedabove, in some embodiments, downlink and uplink transport signalsbetween the central area node and wireless access points may betransported through a transport extension node. The transport extensionnode may be connected to the wireless access points through patchcables, or alternately via virtual cables over the backbone network.Similarly, for embodiments that include a wide-area integration node,the base stations may optionally be connected to the wide-areaintegration node via virtual cables over the backbone network when thebase station downlink signals and the base station uplink signals aredigital signals.

In other words, the components of the DAS (such as the wide-areaintegration node, central area node, and/or transport extension node)need not be coupled to each other a dedicated cabling system but insteadmay communicate digital RF and control signals between each other viathe backbone network. Each virtual cable may comprise distinct uplinkand downlink communications subchannels. However, it should beunderstood that inclusion of physical patch cables is not precluded. Inalternate embodiments, any combinations of virtual and patch cables maybe used. For example, patch cables may be utilized where DAS componentsare conveniently co-located or where virtual cables cannot beestablished due to lack of access to the backbone network. For example,in some embodiments the transport extension node may be coupled towireless access points using patch cables distributed to one or moreantenna locations where the access points are deployed. In otherembodiments, virtual cables on the backbone network may instead be usedto connect the transport extension node to one or more of the accesspoints (e.g. remote antenna units) at their remote locations. Moreover,the method may be implemented using any of the DAS configurationsdescribed in FIGS. 1, 1A-1C, 2-5, or parts thereof, or otherconfigurations.

Regardless of the DAS configuration, each access point receives thedownlink transport signals, converts those digital signals to analogradio frequency (RF) signals for over-the-air transmission, andbroadcasts (radiates) the analog RF signals as wireless downlink RFsignals to user equipment within the coverage area of the distributedantenna system. Uplink wireless RF signals transmitted by the userequipment located within the coverage area of the distributed antennasystem are received by the access points, converted to digital signals,and transmitted up to the central area node as the uplink transportsignals.

As illustrated in FIGS. 2-4 above, in some embodiments, the method mayalso comprise coupling a plurality of wide-area integration nodes to thebackbone network, each coupled to a different set of base stations. Insome embodiments, the method may comprise coupling a plurality oftransport extension nodes to the backbone network, each coupled to adifferent set of base stations. In such embodiments, each of thewide-area integration nodes and transport extension nodes may eachcommunicate over the backbone network (either with each other or througha central area node) via a respective virtual cable. As such, in someembodiments, the method further comprises expanding the coverage area ofthe distributed antenna system by coupling one or more additionaltransport extension nodes to the backbone network and creating arespective virtual cable for each of the one or more additionaltransport extension nodes. Each of the additional transport extensionnodes would be connected to one or more additional access points thusextending the physical area in which user devices may connect to thedistributed antenna system. In some embodiments, the method furthercomprises expanding the service capacity of the distributed antennasystem by coupling one or more additional wide-area integration nodes tothe backbone network and creating a respective virtual cable for each ofthe one or more additional wide-area integration nodes. Each of theadditional wide-area integration nodes would be connected to one or moreadditional base stations thus increasing the capacity and wirelessservices available to user devices within the coverage area of thedistributed antenna system.

In some embodiments, such as shown in FIG. 7, the functions of any ofthe BTS 105 discussed herein may be executed by a distributed BTS 700comprising a Central Unit (CU) 712, a Distribution Unit (DU) 714 and aRemote Radio Unit (RRU) 716. In some embodiments, the distributed BTS700 comprises a 3GPP 5G RAN architecture radio base station (known as agNB) connected to a 5G core network, or may comprise another form ofdistributed radio base station. Further embodiments may thereforeinclude the implementation of such a distributed BTS 700 by utilizingvirtual cable connections via general purpose public infrastructurebackbone networks and a DAS implementation as disclosed herein. Forexample, FIG. 8 illustrates an example embodiment where the CU 712, DU714 and/or RRU 716 are communicatively coupled via the backbone network108 via virtual cables 720 that each define dedicated data channels onthe backbone network 108 for carrying digital transmission of signalsand control data between components of the BTS 700. Each virtual cable720 may comprise distinct uplink and downlink communicationssubchannels. In the embodiment of FIG. 8, a first virtual cable 720forms the midhaul link between the CU 712 and the DU 714. A secondvirtual cable 720 forms the fronthaul link between the DU 714 and theRRU 716. In alternate configurations, either the midhaul and/or thefronthaul may be carried by virtual cables 720. The DAS 100 thencommunicates uplink and downlink basestation signals between the WIN 110and RRU 716 and operates to provide the wireless services of thedistributed BTS 700 via the AP 140 as discussed above. As describedpreviously, components such as the CU 712, DU 714 and/or RRU 716 may becoupled to the backbone network 108 and virtual cables 720 by respectiveadd/drop multiplexers or Ethernet switches (shown at 106).

FIG. 9 illustrates an alternate embodiment where the DAS 100 interfaceswith the distributed BTS 700 between the DU 714 and the RRU 716 suchthat the DAS 100 essentially executes the functions of the RRU 716. Insuch an embodiment, a virtual cable 720 establishes the fronthaul linkbetween the DU 714 and the WIN 110 of DAS 100, and the WIN 110 executesthe function of the RRU 716 to process downlink signals received fromthe DU 714 for distribution by the DAS 100, and process uplink signalsreceived by the DAS 100 for transport to the DU 714. In someembodiments, the functions of the RRU 716 assumed by the DAS 100 may bedistributed between the WIN 110 and the CAN 120. FIG. 10 illustratesanother alternate embodiment where the DAS 100 interfaces with thedistributed BTS 700 between the CU 712 and the DU 714. In thisembodiments, the DAS 100 executes the functions of both the DU 714 andthe RRU 716. In such an embodiment, a virtual cable 720 establishes themidhaul link between the CU 714 and the WIN 110 of DAS 100, and the WIN110 executes the functions of both the DU 714 and the RRU 716 to processdownlink signals received from the CU 712 for distribution by the DAS100, and process uplink signals received by the DAS 100 for transport tothe CU 712. In some embodiments, the functions of the DU 714 and RRU 716assumed by the DAS 100 may be distributed between the WIN 110 and theCAN 120.

Example Embodiments

Example 1 includes a distributed antenna system, the system comprising:a central area node communicatively coupled to a backbone network,wherein the central area node is configured to communicatively couple toat least one base station via the backbone network, the central areanode further configured to communicatively couple to at least onewireless access point via the backbone network; wherein the distributedantenna system is configured to use a plurality of virtual cablesimplemented using the backbone network, each of the plurality of virtualcables defined by a respective dedicated data channel on the backbonenetwork; wherein the central area node is communicatively coupled to theat least one base station and the at least one wireless access pointusing at least some of the virtual cables; wherein downlink transportsignals and uplink transport signals are transported between the centralarea node and the wireless access point through said at least some ofthe virtual cables, wherein the downlink transport signals are generatedfrom base station downlink signals and base station uplink signals aregenerated from the uplink transport signals.

Example 2 includes the system of example 1, further comprising: at leastone wide-area integration node communicatively coupled to the backbonenetwork, wherein the at least one wide-area integration node isconfigured to communicatively couple the distributed antenna system tothe at least one base station, the wide-area integration node configuredto communicate the base station downlink signals and the base stationuplink signals with the at least one base station; wherein the wide-areaintegration node and the central area node are communicatively coupledto one another using the at least some of the virtual cables.

Example 3 includes the system of example 2, wherein the at least onewide-area integration node receives analog radio frequency (RF) basestation downlink signals from the at least one base station andtransmits analog radio frequency (RF) base station uplink signals to theat least one base station.

Example 4 includes the system of any of examples 2-3, wherein the atleast one wide-area integration node converts the analog radio frequency(RF) base station downlink signals into a digital downlink transportsignal for transport over the plurality of virtual cables.

Example 5 includes the system of any of examples 2-4, wherein the atleast one wide-area integration node receives digitized radio frequency(RF) base station downlink signals from the at least one base stationand transmits digitized radio frequency (RF) base station uplink signalsto the at least one base station.

Example 6 includes the system of any of examples 2-5, wherein the atleast one wide-area integration node comprises a first wide-areaintegration node coupled to a central area node by the plurality ofvirtual cables, and a second wide-area integration node coupled to thecentral area node by the plurality of virtual cables, wherein the firstwide-area integration node is configured to communicate a first set ofbase station downlink signals and base station uplink signals with afirst base station, wherein the second wide-area integration node isconfigured to communicate a second set of base station downlink signalsand base station uplink signals with a second base station; wherein thecentral area node is configured to distribute combined wireless servicesof the first base station and the second base station within a coveragearea of the distributed antenna system through the at least one radiofrequency wireless access point.

Example 7 includes the system of any of examples 1-6, furthercomprising: at least one transport extension node communicativelycoupled to the backbone network, wherein the transport extension node iscoupled to the at least one wireless access point; wherein the at leastone transport extension node and the central area node arecommunicatively coupled to one another using the at least some of thevirtual cables.

Example 8 includes the system of example 7, wherein the at least onetransport extension node comprises a first transport extension nodecoupled to a central area node by the plurality of virtual cables, and asecond transport extension node coupled to the central area node by theplurality of virtual cables, wherein the first transport extension nodeis coupled to a first plurality of radio frequency wireless accesspoints, and wherein the second transport extension node coupled to asecond plurality of radio frequency wireless access points; wherein thecentral area node is configured to distribute wireless services of atleast one base station within a coverage area of the distributed antennasystem through the first plurality of radio frequency wireless accesspoints and the second plurality of radio frequency wireless accesspoints.

Example 9 includes the system of any of examples 1-8, wherein thebackbone network comprises at least one of: a Synchronous DigitalHierarchy Network (SDH), a Synchronous Optical Network (Sonet), anOptical Transport Network (OTN), or an Ethernet Network.

Example 10 includes the system of any of examples 1-9, wherein thebackbone network comprises at least one of: the Internet; or a publicinfrastructure network.

Example 11 includes the system of any of examples 1-10, wherein theplurality of virtual cables are each data channels on the backbonenetwork comprising distinct uplink and downlink communicationssubchannels.

Example 12 includes the system of any of examples 1-11, wherein thecentral area node combines uplink signals received from the at least onwireless access point.

Example 13 includes the system of any of examples 1-12, wherein thecentral area node is configurable to manage which of the at least onebase station services are accessible through which of the plurality ofaccess points.

Example 14 includes the system of any of examples 1-13, wherein the atleast one wireless access point comprises a plurality of radio frequencywireless access points.

Example 15 includes the system of any of examples 1-14, wherein the atleast one radio frequency wireless access point receives the downlinktransport signal, converts the downlink transport signal to analog radiofrequency (RF) signals for over-the-air transmission, and broadcasts theanalog radio frequency (RF) signals as wireless downlink RF signals toone or more user devices within a coverage area of the distributedantenna system.

Example 16 includes the system of any of examples 1-15, furthercomprising a common management system, wherein the common managementsystem is configured to send control commands and obtain statusinformation from the central area node and configure the backbonenetwork through a backbone network management interface.

Example 17 includes a method for a distributed antenna system, themethod comprising: communicatively coupling a central area node of thedistributed antenna system to a backbone network, wherein the centralarea node is configured to communicatively couple to at least one basestation via the backbone network, the central area node furtherconfigured to communicatively couple to at least one wireless accesspoint via the backbone network; establishing a plurality of virtualcables implemented using the backbone network, each of the plurality ofvirtual cables using a respective data channel of the backbone network,wherein the central area node is communicatively coupled to the at leastone base station and the at least wireless access point using at leastsome of the virtual cables; and transporting downlink transport signalsand uplink transport signals between the central area node and the atleast one wireless access point through said at least some of theplurality of virtual cables, wherein the downlink transport signals aregenerated from base station downlink signals from the to at least onebase station and base station uplink signals to the at least one basestation are generated from the uplink transport signals.

Example 18 includes the method of example 17, further comprising:communicatively coupling at least one wide-area integration node of thedistributed antenna system to the backbone network, wherein the at leastone wide-area integration node is configured to communicatively couplethe distributed antenna system to the at least one base station, thewide-area integration node configured to communicate the base stationdownlink signals and the base station uplink signals with at least onebase station; communicatively coupling at least one transport extensionnode of the distributed antenna system to the backbone network, whereinthe transport extension node is coupled to the at least one wirelessaccess point; and transporting the downlink transport signals and theuplink transport signals between the wide-area integration node andwireless access point through the central area node via at least some ofthe plurality of virtual cables.

Example 19 includes the method of example 18, wherein the at least oneof the wide-area integration node, the central area node, and the atleast one transport extension node are coupled to the backbone networkby a respective add/drop multiplexer.

Example 20 includes the method of any of examples 18-19, wherein the atleast one wide-area integration node receives analog radio frequency(RF) base station downlink signals from the at least one base stationand transmits analog radio frequency (RF) base station uplink signals tothe at least one base station.

Example 21 includes the method of any of examples 18-20, wherein the atleast one wide-area integration node receives digital radio frequency(RF) base station downlink signals from the at least one base stationand transmits digital radio frequency (RF) base station uplink signalsto the at least one base station.

Example 22 includes the method of any of examples 18-21, furthercomprising expanding a coverage area of the distributed antenna systemby coupling one or more additional transport extension nodes to thebackbone network and creating a respective virtual cable for each of theone or more additional transport extension nodes.

Example 23 includes the method of any of examples 18-22, furthercomprising expanding a service capacity of the distributed antennasystem by coupling one or more additional wide-area integration nodes tothe backbone network and creating a respective virtual cable for each ofthe one or more additional wide-area integration nodes.

Example 24 includes the method of any of examples 17-23, wherein thebackbone network comprises at least one of: a Synchronous DigitalHierarchy Network (SDH), a Synchronous Optical Network (Sonet), anOptical Transport Network (OTN), or an Ethernet Network.

Example 25 includes the method of any of examples 17-24, wherein thebackbone network comprises at least one of: the Internet; or a publicinfrastructure network.

Example 26 includes the method of any of examples 17-25, wherein theplurality of virtual cables are each data channels on the backbonenetwork comprising distinct uplink and downlink communicationssubchannels.

In various alternative embodiments, system and/or device elements,method steps, or example implementations described throughout thisdisclosure (such as any of the wide-area integration node, central areanode, transport extension node, master unit, head-end unit, remoteantenna unit, access point, base station, interfaces, or sub-parts ofany thereof, for example) may be implemented at least in part using oneor more computer systems, field programmable gate arrays (FPGAs), orsimilar devices comprising a processor coupled to a memory and executingcode to realize those elements, steps, processes, or examples, said codestored on a non-transient hardware data storage device. Therefore, otherembodiments of the present disclosure may include elements comprisingprogram instructions resident on computer readable media which whenimplemented by such computer systems, enable them to implement theembodiments described herein. As used herein, the term “computerreadable media” refers to tangible memory storage devices havingnon-transient physical forms. Such non-transient physical forms mayinclude computer memory devices, such as but not limited to punch cards,magnetic disk or tape, any optical data storage system, flash read onlymemory (ROM), non-volatile ROM, programmable ROM (PROM),erasable-programmable ROM (E-PROM), random access memory (RAM), or anyother form of permanent, semi-permanent, or temporary memory storagesystem or device having a physical, tangible form. Program instructionsinclude, but are not limited to, computer-executable instructionsexecuted by computer system processors and hardware descriptionlanguages such as Very High-Speed Integrated Circuit (VHSIC) HardwareDescription Language (VHDL).

As used herein, terms such as “wide-area integration node”, “centralarea node”, “transport extension node”, “master unit”, “head-end unit”,“remote antenna unit”, “access point”, “base station”, each refer tonon-generic device elements of a distributed antenna system that wouldbe recognized and understood by those of skill in the art and are notused herein as nonce words or nonce terms for the purpose of invoking 35USC 112(f).

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement, which is calculated to achieve the same purpose,may be substituted for the specific embodiment shown. This applicationis intended to cover any adaptations or variations of the presentedembodiments. Therefore, it is manifestly intended that embodiments belimited only by the claims and the equivalents thereof.

What is claimed is:
 1. A distributed antenna system, the systemcomprising: a central area node communicatively coupled to a backbonenetwork, wherein the central area node is configured to communicativelycouple to at least one base station via the backbone network, thecentral area node further configured to communicatively couple to atleast one wireless access point via the backbone network; wherein thedistributed antenna system is configured to use a plurality of virtualcables implemented using the backbone network, each of the plurality ofvirtual cables defined by a respective dedicated data channel on thebackbone network; wherein the central area node is communicativelycoupled to the at least one base station and the at least one wirelessaccess point using at least some of the virtual cables; and whereindownlink transport signals and uplink transport signals are transportedbetween the central area node and the wireless access point through saidat least some of the virtual cables, wherein the downlink transportsignals are generated from base station downlink signals and basestation uplink signals are generated from the uplink transport signals.2. The system of claim 1, further comprising: at least one wide-areaintegration node communicatively coupled to the backbone network,wherein the at least one wide-area integration node is configured tocommunicatively couple the distributed antenna system to the at leastone base station, the wide-area integration node configured tocommunicate the base station downlink signals and the base stationuplink signals with the at least one base station; wherein the wide-areaintegration node and the central area node are communicatively coupledto one another using the at least some of the virtual cables.
 3. Thesystem of claim 2, wherein the at least one wide-area integration nodereceives analog radio frequency (RF) base station downlink signals fromthe at least one base station and transmits analog radio frequency (RF)base station uplink signals to the at least one base station.
 4. Thesystem of claim 2, wherein the at least one wide-area integration nodeconverts analog radio frequency (RF) base station downlink signals intoa digital downlink transport signal for transport over the plurality ofvirtual cables.
 5. The system of claim 2, wherein the at least onewide-area integration node receives digitized radio frequency (RF) basestation downlink signals from the at least one base station andtransmits digitized radio frequency (RF) base station uplink signals tothe at least one base station.
 6. The system of claim 2, wherein the atleast one wide-area integration node comprises a first wide-areaintegration node coupled to a central area node by the plurality ofvirtual cables, and a second wide-area integration node coupled to thecentral area node by the plurality of virtual cables, wherein the firstwide-area integration node is configured to communicate a first set ofbase station downlink signals and base station uplink signals with afirst base station, wherein the second wide-area integration node isconfigured to communicate a second set of base station downlink signalsand base station uplink signals with a second base station; wherein thecentral area node is configured to distribute combined wireless servicesof the first base station and the second base station within a coveragearea of the distributed antenna system through the at least one wirelessaccess point.
 7. The system of claim 1, further comprising: at least onetransport extension node communicatively coupled to the backbonenetwork, wherein the transport extension node is coupled to the at leastone wireless access point; wherein the at least one transport extensionnode and the central area node are communicatively coupled to oneanother using the at least some of the virtual cables.
 8. The system ofclaim 7, wherein the at least one transport extension node comprises afirst transport extension node coupled to a central area node by theplurality of virtual cables, and a second transport extension nodecoupled to the central area node by the plurality of virtual cables,wherein the first transport extension node is coupled to a firstplurality of radio frequency wireless access points, and wherein thesecond transport extension node coupled to a second plurality of radiofrequency wireless access points; wherein the central area node isconfigured to distribute wireless services of at least one base stationwithin a coverage area of the distributed antenna system through thefirst plurality of radio frequency wireless access points and the secondplurality of radio frequency wireless access points.
 9. The system ofclaim 1, wherein the backbone network comprises at least one of: aSynchronous Digital Hierarchy Network (SDH); a Synchronous OpticalNetwork (Sonet); an Optical Transport Network (OTN); or an EthernetNetwork.
 10. The system of claim 1, wherein the backbone networkcomprises at least one of: the Internet; or a public infrastructurenetwork.
 11. The system of claim 1, wherein the plurality of virtualcables are each data channels on the backbone network comprisingdistinct uplink and downlink communications subchannels.
 12. The systemof claim 1, wherein the central area node combines uplink signalsreceived from the at least on wireless access point.
 13. The system ofclaim 1, wherein the central area node is configurable to manage whichof the wireless services of the at least one base station are accessiblethrough which of the plurality of wireless access points.
 14. The systemof claim 1, wherein the at least one wireless access point comprises aplurality of radio frequency wireless access points.
 15. The system ofclaim 1, wherein the at least one wireless access point receives thedownlink transport signal, converts the downlink transport signal toanalog radio frequency (RF) signals for over-the-air transmission, andbroadcasts the analog radio frequency (RF) signals as wireless downlinkRF signals to one or more user devices within a coverage area of thedistributed antenna system.
 16. The system of claim 1, furthercomprising a common management system, wherein the common managementsystem is configured to send control commands and obtain statusinformation from the central area node and configure the backbonenetwork through a backbone network management interface.
 17. The systemof claim 1, wherein the at least one base station comprises adistributed base station.
 18. The system of claim 17, wherein thedistributed base station comprises a central unit, a distribution unit,and a remote radio unit; wherein the distributed antenna systeminterfaces with the distributed base station either: at the output ofthe remote radio unit; between the distribution unit and the remoteradio unit, wherein the distributed antenna system is further configuredto execute one or more functions of the remote radio unit; or betweenthe central unit and the distribution unit, wherein the distributedantenna system is further configured to execute one or more functions ofthe distribution unit and the remote radio unit.
 19. The system of claim17, wherein the distributed base station comprises a central unit, adistribution unit, and a remote radio unit; wherein one or more of thecentral unit, the distribution unit, and the remote radio unit arecommunicatively coupled by at least some of the plurality of virtualcables defined on the backbone network.
 20. A method for a distributedantenna system, the method comprising: communicatively coupling acentral area node of the distributed antenna system to a backbonenetwork, wherein the central area node is configured to communicativelycouple to at least one base station via the backbone network, thecentral area node further configured to communicatively couple to atleast one wireless access point via the backbone network; establishing aplurality of virtual cables implemented using the backbone network, eachof the plurality of virtual cables using a respective data channel ofthe backbone network, wherein the central area node is communicativelycoupled to the at least one base station and the at least wirelessaccess point using at least some of the virtual cables; and transportingdownlink transport signals and uplink transport signals between thecentral area node and the at least one wireless access point throughsaid at least some of the plurality of virtual cables, wherein thedownlink transport signals are generated from base station downlinksignals from the at least one base station and base station uplinksignals to the at least one base station are generated from the uplinktransport signals.
 21. The method of claim 20, further comprising:communicatively coupling at least one wide-area integration node of thedistributed antenna system to the backbone network, wherein the at leastone wide-area integration node is configured to communicatively couplethe distributed antenna system to the at least one base station, thewide-area integration node configured to communicate the base stationdownlink signals and the base station uplink signals with at least onebase station; communicatively coupling at least one transport extensionnode of the distributed antenna system to the backbone network, whereinthe transport extension node is coupled to the at least one wirelessaccess point; and transporting the downlink transport signals and theuplink transport signals between the wide-area integration node andwireless access point through the central area node via at least some ofthe plurality of virtual cables.
 22. The method of claim 21, wherein theat least one of the wide-area integration node, the central area node,and the at least one transport extension node are coupled to thebackbone network by a respective add/drop multiplexer.
 23. The method ofclaim 21, wherein the at least one wide-area integration node receivesanalog radio frequency (RF) base station downlink signals from the atleast one base station and transmits analog radio frequency (RF) basestation uplink signals to the at least one base station.
 24. The methodof claim 21, wherein the at least one wide-area integration nodereceives digital radio frequency (RF) base station downlink signals fromthe at least one base station and transmits digital radio frequency (RF)base station uplink signals to the at least one base station.
 25. Themethod of claim 21, further comprising expanding a coverage area of thedistributed antenna system by coupling one or more additional transportextension nodes to the backbone network and creating a respectivevirtual cable for each of the one or more additional transport extensionnodes.
 26. The method of claim 21, further comprising expanding aservice capacity of the distributed antenna system by coupling one ormore additional wide-area integration nodes to the backbone network andcreating a respective virtual cable for each of the one or moreadditional wide-area integration nodes.
 27. The method of claim 20,wherein the backbone network comprises at least one of: a SynchronousDigital Hierarchy Network (SDH); a Synchronous Optical Network (Sonet);an Optical Transport Network (OTN)); or an Ethernet Network.
 28. Themethod of claim 20, wherein the backbone network comprises at least oneof: the Internet; or a public infrastructure network.
 29. The method ofclaim 20, wherein the plurality of virtual cables are each data channelson the backbone network comprising distinct uplink and downlinkcommunications subchannels.